#lunkuo{
    position: absolute;
    top: 50%;/*顶部到元素*/
    left:30%;
    width: 40%;
    height:420px;
    margin-top:-200px;/*边缘到底部*/
    background-color: #808080;
    text-align-last: center;
    filter:alpha(Opacity=60);-
moz-opacity:0.6;
    opacity: 0.6;
}
#lunkuo input{
    font-size: 20px;
    text-align: center;
    border-radius: 25px;
}